For the first time since March 2011, 31-year-old Rafael Nadal and 36-year-old Roger Federer are officially the world's top two men’s tennis players.

With a combined age of 67, that is the oldest pairing the men's game has seen since rankings began in 1973.

And following Nadal's blistering win in New York on Sunday night, it also means the duo hold all four Grand Slams for the first time since 2010.

Not since 1969 have all four majors been won by a player aged 30+ (Rod Laver's calendar Grand Slam aged 30 and the 31 for the US), making Federer and Nadal's 2017 achievements quite comfortably a record, if you were to add up their age following each victory…

Australian Open, 2017

Roger Federer

35

French Open, 2017

Rafael Nadal

31

Wimbledon, 2017

Roger Federer

35

US Open, 2017

Rafael Nadal

31

Combined Age: 132

Australian Open, 1972

Ken Rosewall

37

French Open, 1972

Andres Gimeno

34

Wimbledon, 1972

Stan Smith

25

US Open, 1972

Ilie Nastase

26

Combined age: 122

So in what will go down as the year of Roger and Rafa's return, do we celebrate these two great champions defying age and belief, or do we despair at the lack of competition in men’s tennis?

It is, of course, for the purpose of pure hyperbole that the word despair is used, but some concerns have cropped up from the year that was in Grand Slam tennis.

After the duo met in a pulsating Australian Open final, Nadal went on to drop a total of zero sets en route to French Open victory, while Federer did likewise at Wimbledon.

And while Nadal’s victory at Flushing Meadows was not plain-sailing, the relative ease by which he or Federer won each major this year is undeniably alarming.

The point remains, that even at 36 and 31 respectively, the prospect of seeing both Federer and Nadal ousted over five sets before a final takes place is a near-impossible task.

Only Juan Martin del Potro (US Open quarter v Federer) and Gilles Muller (Wimbledon last 16 v Nadal) can tell you what that feels like this year.

Meanwhile, the three men who could outlast them in recent years ultimately succumbed to injury, and were not even able to compete at the US Open.

In Andy Murray’s case, it’s worth remembering more his tireless dedication it took to become world number one than it is to recall his actual stint at the top of the tree, for an ailing body finally took its toll.

Same too for Novak Djokovic, who failed to reach a Grand Slam semi-final for the first year since 2006. Once again, that’s a testimony to his longevity, but a longstanding elbow injury saw him call time on the 2017 season back in July.

Andy Murray endured a tough 2017, struggling with a hip problem for the majorityGetty Images

And finally, Stan Wawrinka, who also cut his season short due to injury, having suffered a first-round exit in Wimbledon after a run to the Aussie Open semis and French Open final.

The trio’s absence (add Kei Nishikori and Milos Raonic to that list, too) at the US Open was a reminder of how bruising the ATP calendar can be, and a depleted line-up was there for Federer and Nadal’s taking.

Of course, Del Potro had his say on the matter, but even the affable Argentine could not prevent Nadal, even after taking the first set in their last-four meeting.

A greater concern lies with where the next maiden Grand Slam champion will come from.

The much-heralded Alexander Zverev fell early to fellow ‘NextGen’ star Borna Coric, ending a season of promise – having won two Masters titles – with a best finish of the fourth round at a Grand Slam (Wimbledon).

The duo are arguably the standout champions-in-waiting, but this year served as a reminder of what it takes both physically and mentally to win a Grand Slam.

It was far from complete doom and gloom in New York for the younger players; 18-year-old Denis Shapovalov wowed crowds on his way to the last 16, 19-year-old Andrey Rublev impressed as he made the quarters, while Frances Tiafoe, also 19, displayed his terrifying potential in the five-set loss to Federer.

All valiant showings, but all some distance short of a Grand Slam-winning performance.

It’s clear men’s tennis is at a crossroads as it patiently waiting for the young crop to take the mantle, so while we pause at this junction of uncertainty, why not enjoy the nostalgic hit which is Roger and Rafa’s resurgence.

-Eurosport

The duo, sharing the Grand Slams two apiece for the first time (surprisingly, no pair has done this before), have reminded us that age is just a number, and who’s to say won’t see a clean sweep repeat in 2018?

Federer and Nadal have retained the baton in men's tennis, much to the delight of Fedal fanatics, but it’s time for a new name to take it onto the next leg. The question of 'Who?' could persist for some time yet.